Banded projectiles particularly for small arms



Jan. 31, 1967 H Y 3,301,186

BANDED PROJECTILES PARTICULARLY FOR SMALL ARMS Filed Aug. 11, 1964 United States Patent 3,301,186 BANDED PROJECTILES PARTICULARLY- FOR SMALL ARMS Charles Henry, Cusset-Allier, France, assignor to Manufacture de Machines du Haut-Rhin, Mulhouse-Bourtz Willer, France Filed Aug. 11, 1964, Ser. No. 388,855 Claims priority, application France, Aug. 12, 1963, 944,448 6 Claims. (Cl. 102-93) The present invention relates to banded projectiles and more particularly to banded projectiles for small arms.

The driving band of a banded projectile serves to ensure sealing tightness between the bore of the barrel and the projectile and to impart to the projectile a rotary movement which ensures its stability in the trajectory. For this purpose, the driving band should be able to conform itself to the internal profile of the barrel, be hard enough not to be worn by the rifling of the barrel and to be sufficiently well fixed to the projectile to drive it in its rotary movement.

In default of an ideal solution, driving bands are usually of copper or of Steel, materials which cause respectively copper fouling and rapid wear of barrels; if made of sintered steel or iron they are moreover apt to break up partially and to give off jets of sparks at the mouth of the barrel.

In the particular case of small arms ammunition, the driving band is generally constituted by a steel envelope plated with nickel or German silver which is mounted either directly on the body of the projectile when the latter is of lead, or else with the inter-position of a lead sleeve when the body is of tempered steel. The main purpose of the lead sleeve in this case is to permit the steel envelope to deform as it engages the rifling. Consequently, without the lead sleeve, which forms a deformable mattress, the friction of the projectile would cause too rapid wear of the barre-l. Moreover, when the envelope of the projectile has effectively the form of a band, the connection between the subjacent lead ring and the thin external steel band is not always sufiicient to resist the inertia forces developed during the setting in rotation of the projectile in the barrel.

The object of the invention is to overcome these drawbacks.

More precisely, the present invention concerns a banded projectile in which the contact between the driving band and the body of the projectile is realised without the interposition of a lead sleeve, the driving band being capable of conforming itself to the internal profile of the barrel on the one hand, while concerning moreover correct connection with the body of the projectile.

In a first particular form of the invention, the driving band and the body of the projectile are directly in contact, but this contact is not continuous, so that there exists between the driving band and the said body a plurality of cavities which permit the driving band to deform under the action of the rifling of the bore during firing.

In a preferred form of embodiment, the body of the projectile is formed with a system of fine grooves which are inclined in the direction of rotation of the projectile, the depth of the groove about corresponding to the depth of the rifling in the bore, and the longitudinal profile of the grooved portion being selected in such a manner that the driving band, once put in position, is exactly the profile which suits best the particular conditions of use. The grooves can also be inclined in the opposite direction to that of rotation.

This system of grooves possesses effectively the qualities required for connecting means between body and driving band since it permits the driving band to deform, taking into account that the volume of the bands is about v 3,301,186 Patented Jan. 31, 1967 "ice equal to the volume of the spaces while offering sufficient resistance to the lateral shearing.

According to another form of the invention, the driving band which is applied on the system of grooves thus formed is constituted by a thin ring, for example of coldworked mild steel which is plated with nickel or German silver; the thickness of this is preferably between 0.5 and 1 mm.

The fixing of this driving band on the body of the projectile is effected, according to another feature of the invention, in forming on the body of the projectile, on each side of the grooved portion, two transverse circular channels, having a suitable profile and an external lip, then in applying the cylindrical ring onto the groove by means of a positioning ring of rubber for example, and thereafter pressing down the external lips of the channels onto the edges of the driving band in such a manner as to push down these edges to the bottom of the channels. The positioning operation for the driving band could also be effected by magnetic forming.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a half-view of the projectile body of the first embodiment,

FIG. 2 is a half-view of the projectile body of the sec ond embodiment,

FIG. 3 is a side view in half-section of the embodiment of FIG. 1 with the ring in position,

FIG. 4 is a side view half in section of the embodiment shown in FIG. 2 with the ring in position, and

FIG. 5 is a section of the projectile at right-angles to its axis showing the profile of the ring, and of the system of subjacent grooves, before and after firing (the state after firing being shown in the top right quadrant).

In FIGS. 1 and 2 is shown one half of a side view of the body of the projectile, one of which is formed in accordance with the invention, on the one hand a system 2 of fine grooves inclined in the direction of the rotation of the projectile, and on the other hand a plane perpendicular in the axis of the projectile to channels 3 and 4 the edges of which present external lips 5 and 6, FIGS. 1 and 2 differing only in the shape of the grooves.

The ring which is then placed in contact with the grooved portion of the body of the projectile and of which the edges are forced into the grooves of this body by pushing down on them, by means of a dowel or by any other means, the external lips, is shown in FIGS. 3 and 4 which correspond respectively to FIGS. 1 and 2, and which show each a side view with the left half in section, of the body of the projectile 1 provided with its driving band 7 of which the edges 8 and 9 are forced respectively to the bottom of the grooves 3 and 4 under the pusheddown lips 5 and 6. It will be noticed that in the halfsections on the left of FIGS. 3 and 4 the system of grooves 2 are shown in continuous lines for greater clarity, whereas they would normally be shown in dotted lines.

When seen in section at right-angles to the axis of the projectile, the driving band has the profile indicated in FIG. 5, the driving band 7 resting over the grooves 2 of the body of the projectile; the upper right-hand quadrant in this same figure shows the partial crush of this groove system following the deformation of the driving band after firing under the effect of the rifling of the barrel.

It will be understood that for a projectile of given shape and dimensions, a driving band of this form leads to a diminution in weight and that for an envelope obtained by cold-working it increases the internal volume of the shell and thus permits the introduction of the greater charge of explosive.

In the case of a steel piercing projectile having a driving band, the method of providing the driving band would be the same since a softening treatment of the whole portion behind the shell is generally necessary and enables a hardness to be obtained at the points where it is necessary such that the positioning and use of the driving band take place without difficulty.

It is within the contemplation of the present invention also that the plurality of fine grooves 2 are generally in skew relation, otherwise expressed as being parallel to a direction inclined, to the axis of the body 1 and therefore helical in form, that the depth of the grooves 2 corresponds generally to the depth of rifiing grooves in the bore (not shown) for said projectile, as pointed out above as one of the preferred forms of the invention, and that the walls of said grooves may be superficially annealed.

What I claim is:

1. A projectile to be fired by firearms having a barrel with inside rifiing grooves, said projectile comprising a body having an axis of revolution, a generally tubular mild steel driving band having inner and outer cylindrical surfaces encircling a portion of said body, said 'portion of said body provided with a grooved structure defining top ridges and hollow bottoms, said top ridges being in immediate and continuous contact with said inner cylindrical surface of said driving band and defining air spaces between said inner cylindrical surface of said band and said of said grooved structure is substantially equal to the depth of said rifiing grooves.

3. A projectile according to claim 1, wherein said top ridges of said grooved structure are inclined in the direction of rotation of said projectile.

4. A projectile according to claim 1, in which said top ridges and hollow bottoms of said grooved structure are parallel to a direction inclined to said axis of said projectile.

5. A projectile according to claim 1, wherein said means adjacent said portion are annular channels in said body, said channels form lips which secure ends of said driving band.

6. A projectile according to claim 1, in which said body is made of steel, said grooved structure being superficially annealed.

References Cited by the Examiner UNITED STATES lATENTS 815,992 3/1906 Wheeler et al 102-93 1,361,158 12/1920 Jezler 10293 1,526,701 2/1925 Fa'hrenwald 102-93 X FOREIGN PATENTS 137,193 5/1950 Australia.

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

R. P. STAHL, Assistant Examiner. 

1. A PROJECTILE TO BE FIRED BY FIREARMS HAVING A BARREL WITH INSIDE RIFLING GROOVES, SAID PROJECTILE COMPRISING A BODY HAVING AN AXIS OF REVOLUTION, A GENERALLY TUBULAR MILD STEEL DRIVING BAND HAVING INNER AND OUTER CYLINDRICAL SURFACES ENCIRCLING A PORTION OF SAID BODY, SAID PORTION OF SAID BODY PROVIDED WITH A GROOVED STRUCTURE DEFINING TOP RIDGES AND HOLLOW BOTTOMS, SAID TOP RIDGES BEING IN IMMEDIATE AND CONTINUOUS CONTACT WITH SAID INNER CYLINDRICAL SURFACE OF SAID DRIVING BAND AND DEFINING AIR SPACES BETWEEN SAID INNER CYLINDRICAL SURFACE OF SAID BAND AND SAID HOLLOW BOTTOMS, MEANS ADJACENT SAID PORTION OF SAID BODY FOR SECURING SAID BAND TO SAID BODY AND A PLATED METAL COATING ON SAID OUTER CYLINDRICAL SURFACE SELECTED FROM THE GROUP CONSISTING OF NICKEL AND GERMAN SILVER. 